Contour forming machine



Nov. 24, 194 c. c. MISFELDT CONTOUR FORMING MACHINE 2 Sheefs-Sheet 1 Filed March 11, 1940 [N VENTOR CHARLES C. M/SFELD T A TTORNE Y Nov. 24, 1942. g, c, NHSFELDT 2,303,058

'CON'I'OUR FORMING MACHINE Filed March 11, 1940 2 Sheets-Sheet 2 i H IL U P u INVENTORY CH4PLE5 C. M/SFELDT A TTORNEY Patented Nov. 24, 1942 QONTOUR FORMING MACHINE Charles C. Misleldt, Glendale, Calii'., assignor to Douglas Aircraft Compa Calif.

ny, Inc., Santa Monica.

Application March 11, 1940, Serial No. 323,411 9 Claims! (Cl. 153-48) My invention relates to-a contour io'rming,

machine in which a piece of material is bent about the perimeter oi-a forming block and is thus caused to assume the configuration of the perimeter.

This machine eliminatesthe time-consuming I hand work which has previously been necessary to form irregular, non-arcuate,-and- 'compound contours in sheet, tubular, rod, bar, and extruded". pieces of material of the type which are customarily formed on the perimeter of a forming block. Machines have been developed for forming such material only to true radius contours in a single plane but such a limitation no longer exists for with my machine it is possible to form material of the type specified and other similar pieces to practically any smooth contour which may be desired. Furthermore, it is possible to contour a piece of material which varies in thickness from one end to the other; another operation which was heretofore impossible except by hand working.

Accordingly, it is an object of my invention to provide a machine in which a piece of material may be forced to assume the irregular and nonarcuate configuration of a form block perim- 4 eter.

Another object of my invention is to provide a machine for rotating a form'block with respect to a yieldable forming shoe, the piece of material to be formed being placed between the rotating block and the shoe.

Another object of my invention is to provide a machine for making compound and non-arcuate bends in a piece of material.

Another object of my invention is to provide a machine for forming both true radius and non-arcuate contours in a piece of material of varying thickness.

Still other and further objects will become apparent in the following description and in the drawings in which:

Figure 1 is an exploded perspective view of the component parts of my contour forming machine, the parts being placed in their relative functioning positions.

Figure 2 is a view in elevation of my complete forming machine set up on a table or framework in operative condition.

Figure 3 is an exploded perspective view of a portion of a forming block and a forming shoe ,as-u'sed in the machine for contouring a T-sectioned piece of material. I

Figure 4 is an exploded perspective view cl 9. portion of a forming block and a forming shoe as Y the fluid to exhaust from the cylinder through v used in the-machine forcontouring a tonguedtubular section of material, together with a' mandrel for preventing the hollow 'tube fromclosing during the forming Operation.

Figure 5 is a'per spective view of a variation in themounting-of the forming shoe as use in making compoundbends.;-in material; and

Figure 6 is a perspective .view'z'ef a i'orming blocksuitable for use in 'my machine for rn'ak I ing compound bends in material in conjunction with the flexiblymounted shoe or Figure 5.

- In Figure 1 is shown .the relativepositioning.

of parts comprising my contour forming m'achine together with a representative piece of material to be formed about'the perimeter of a forming block. The machine is essentially com-' posed of a cylinder l0 suitable for containing compressed air or other fluid, a piston l2 reciprocable in the cylinder, a shoe l4 mounted on the exterior end of the piston, a rotatable forming block I6 and power means l8 for rotating the block.

Air or other fluid enters an end of the cylinder ill through a port 20 from a supply line 22. A two-way valve 24, when set in one position by a handle 26, permits the release of fluid from the supply'line to the cylinder and, when set in another position, closes the supply line and permits a pipe 28 connected to a valve port 30.

Within the cylinder the piston I2 is adapted ,to reciprocate. This piston has a head 32 on thev interior end thereof together with suitable packing 34 for preventing fluid in the inner end of the cylinder from passing the head. On the exterior and of the piston is fltted a yoke 36 and in this yoke is carried the shoe II. The shoe is pivoted to the yoke at 38 on a vertical axis whereby. it may swing in a horizontal plane with respect to the yoke.

In the horizontal plane of the shoe and spaced therefrom, the rotatable forming block it is mounted and is adapted to be driven by the motor l8 or other power supply through a shaft 42. A clamping device 44 is mounted on the forming block for rotation therewith and, as the forming operation takes place on the perimeter of the block, the clamping. device is adapted to grip an end of the piece of material to be formed to a starting point on the forming perimeter.

A- small block 46 serving as a clamping pad is placed between the clamp and the piece of material to be formed in order that a strong gripping pressure may be had without marring the mate- 'rial.

In Figure 1, the piece of material to be formed about the perimeter of the block i8 is designated by the numeral 48. This piece is an extruded section having a concave side it, a convex side I! and a groove 84 extendin throughout the length of the piece on the top side thereof. In designing a forming block, such as the block i 8, and a shoe, such as the shoe I4, for forming a piece of material with such a cross sectional configuration, both the perimeter of the block and the face of the shoe are shaped to nest with the piece of material. In other words, as shown in the drawings, the shoe has a concave face to nest with 'the convex side of the piece 48, and the forming block perimeter has a convex face to nest with the concave side of the piece. In this manner the piece can be properly held between the shoe and the block as the forming takes place. As may also be seen in the drawings, the block or clamping pad 48 is of the same shape as the shoe on the side which confronts the piece 48.

On pieces of material having hollow portions such as the groove 54 in the piece 48, it is necessary to insert a mandrel in the hollow portion at the point of forming to prevent the hollow portion from closing as the piece is bent about the perimeter of the forming block. I accomplish this with respect to the piece 48 by placing an arm 55 in the piston yoke 88 which arm is adapted to pivot with the shoe l4. At the far end of the arm a laminated spring steel mandrel 58 is attached as by bolts 58, and this mandrel,

. being of laminated spring steel construction, is

flexible and of a size just permitting it to ride in the groove 54 as the piece 48 is formed. The mandrel need be only of a length sufficient to permit it to remain in the forming area.

In setting up my contour forming machine for operation, the cylinder Ill and forming block drive shaft 42 may be attached to a tabl or framework 80 in a manner similar to that shown in Figure 2. The cylinder is mounted. horizontally and the drive shaft vertically in order that the forming block may rotate in a horizontal plane on a level with the shoe l4 carried by the cylinder piston l2. 'The motor l8 for rotating the form block may be suitably mounted below the table top with the drive shaft 42 extending -therethrough. The space between the cylinder l8 arid the shaft 42 is governed by the stroke of the piston l2 and the size of the forming block I8, In other words, this space should be such as will both permit the high point of the forming block to pass the shoe before the piston is fully retracted and permit the shoe to be urged against the low point of the forming block before the piston is fully extended.

To form the piece of material 48 to the contour of the forming block perimeter the operation is as follows: An end 82 of the piece 48 is moved into nesting relation with the forming block perimeter at a starting point thereon. Next, the small block or clamping pad 48 is applied over the Piece and the clamping device 44 is actuated to contact the pad 48 and pull the pad toward the forming block so that the pad and piece are securely gripped against the forming block perimeter. The valve 24 is then set to release air under pressure to the cylinder II, the air entering the cylinder through the port 28, confronting the piston head 82 and forcing the 'piston'to move outward. This outward movement, of course. moves the shoe l4 and the mandrel 58 toward the perimeter of the forming block 18 until the shoe nests with the piece of material to be formed at a location adjacent the clamping device 44. The spring steel mandrel 88 is indexed into the groove 84 and the shoe is urged against the piece 48 and the forming block perimeter. The motor I8 is then started and the forming block rotates in a clockwise direction until the entire forming perimeter has passed the shoe. As the high spots on the block approach and pass the shoe the piston is moved inward against the air pressure in the cylinder. Conversely, as the low spots on the block aproach and pass the shoe the air pressure moves the piston outward in order to maintain the shoe tightly pressed against the piece to be formed.

The pivotal connection between the shoe and mandrel arm and the piston yoke 88 permits the shoe and mandrel arm to move as the block rotates and the face of the shoe therefore remains constantly tangent to the block as it slides along the piece 48, forcing same to conform to the contour of the block's perimeter. The mandrel likewise slides in the groove '4, always riding at the forming point to prevent the groove from closing as the piece 48 is bent. In connection with this sliding action, it is advisable to oil the piece 48 in order that the shoe and mandrel may freely slide with respect thereto. This tends to promote the smoothness of the formin operation and prevent chattering between the shoe and the piece of material.

After the entire forming perimeter has passed the shoe and the piece 48 has been correspondly contoured, the valve 24 in the supply line 22 is set to close the supply line and permit the air in the cylinder to exhaust through the pipe 28. This relieves the pressure on the piston and it may then be moved from contact with the piece 48. The clamping device is next relieved and the completely formed piece may be removed from the forming block.

The yieldable reciprocating shoe feature of the device as just described may likewise be used in forming pieces of material which may vary in thickness throughout their length. Such pieces may be formed to both true radius and non-arouate contours in my machine, the variation in thickness of the piece serving to reciprocate the shoe.

In Figures 3 and 4, I show two other representative shapes which may easily be contoured to a form block perimeter on the machine just described.

The piece of material shown in Figure 3 is a T section, indicated by the numeral 84, and in forming this section the shoe 88 need only be flat in order to contact the top of the T. The forming block 88 however should be specially constructed preferably in layers 88, 9, 18, the layers 88 and 1|! being adapted to receive the body of the 1' between them. The reason for having the plurality of layers is that in forming the section the body of the T has a tendency to swell and it might be difficult to remove the section after forming if a one-piece block were used. The layers 88, 88, it of the forming block may be detachably fastened together as by bolts II in order to allow for removal of the section 84 from the block 88 after the forming is completed. I have stated that in this type of forming operation the shoe 88 need only be flat but this statement should be clarified. It is true that the portion of the shoe contacting the 1' section need only be flat but the shoe itself should preferably be U-shaped in the manner of the yoke 88 with the legs or accepts flanges" of the u overlapping the composite form block as shown. This is in line with the swelling tendency oi the T section, the flanges "serving to aid in preventing the layers 68, 68, of the forming block from spreading. The clamping pad used in this operation is also U- shaped as shown at 14. in forming this type of section.

The piece of material shown in Figure 4 is a tubular section, indicated by the numeral 15, having a tongue extending outward somewhat on a tangent to the tube throughout the length thereof. In forming this piece, the forming block 16 need only have a half-round groove about the perimeter as at 11 in order that approximately one-half of the tubular portion of the piece 15 may nest therein. The shoe 18 for forming this piece has its forming face shaped to take .both the other half of the tubular section'and the tongue as shown in the drawings, the tongue being adapted to slide up into a slot in the face; and the clamping pad 19 is similarly shaped. No particular diificulty is experienced in forming because the tongue portion is on the outside of the bend for supporting the mandrel is the shoe 18 and pivotstherecable carrying the balls reaches point of forming forming block; then as the block the beginning turns, carrying the piece 15 around its perimeter, the mandrel keeps sliding out of the piece.

Compound bends may also a compound bend it is, of course, necessary that the forming shoe move both iz'ontal planes and in a vertical plane. to accomplish this a vertical track 86 is fixed to the piston I2 in place of the yoke 36. Mounted on the track through rollers 88 is a support 90 may be freely movable, rangement 96 extends track 86 and serves as his manner heavy side loads on the piston may be eliminated.

A typical forming block for bend is shown in Figure 6 at I02,jand in order to form a piece of material to the contour of this block a flexibly mounted shoe such described must be used. In other words, the shoe No mandrel is necesssary at the forming in a plurality of horsupport 90 for limited making a compound with respect to the shoe and the as that just of the hump and then straighten out in its original horizontal starting plane as it finishes the forming.

Adjacent the block I02 I have shown a channel section of material at I suitable for forming on this block. When forming a section of this kind, the swelling tendency is also present as in the 1' section previously described. Consequently, the block should be made in three layers I06, I 08, I I 0, detachably bolted together as at I I2, in order to allow for easy removal of the piece I04 ai'ter forming. Likewise, upper and lower flanges III, II6 should be provided on the shoe so that they may lap over the top and bottom sides of the forming block to aid in counteracting the swellstock material may may be made convex or concave, etc. All 01' these variations may be accomplished through changes in the detail design 01' the forming block and forming shoe without departing from the spirit and scope of my invention. After understanding characteristics of the apparatus to accomplish their individual requirements.

I claim:

' 1. In a machine for contouring a piece of material, a forming block having a non-planar perimeter of non-uniform curvature about which piece to be 2. In a machine for terial, a

be formed to laid means for rotating said block In a single plane, means to urge said piece to be formed against said forming perimeter as laid on the track as as it about which the piece block is rotated with respect to said urging means, including a pressure applying means and a pressure shoe to contact said piece of material. and means upon which said pressure shoe is through its contact with the piece of material, on of its normal plane as necessary to follow the contour of the forming block perimeter.

3. In a machine for contouring a piece of material of irregular configuration in cross section, a laminated rotatable contour forming block having a partially curved but non-arcuate perimeter of material is formed, said perimeter being shaped to mate with the conflsuration of one side of the piece of material to be formed, a r'eciprocable yieldable member for urging said piece of material in contact with said perimeter, said yieldabie member being shaped to mate with the configuration of another side of said piece to be formed, and said last named member being reciprocated by the eccentric perimeter of said forming block as said block rotates, and upper and lower flange shaped portions on member adapted to overlap said laminations to counteract swelling thereof as said piece of material lying therebetween is formed.

4. In a machine for contouring a piece of material, a laminated rotatable contour forming block having a perimeter of non-uniform curvature about which the piece of material is formed, a shoe adapted to follow the non-uniform curvature of said perimeter and to hold said piece of material in contact therewith, yieldable means for urging said shoe toward said contour forming block, said yieldable means including a compressed air cylinder and a piston reciprocable therein, a pivotal connection between said shoe and said piston, whereby said shoe may move with said piston and pivot with respect thereto as said shoe follows the eccentric perimeter of said rotating form block, upper and lower flange shaped portions on said shoe adapted to overlap said forming block laminations to counteract swelling thereof as-said piece of material lying therebetween is formed, and means with said shoe for balancing the weight thereof so that it may readily follow the non-uniform curvature of the forming block perimeter.

5. In a machine for contouring a piece of material, a rotatable non-planar contour forming block having a perimeter of non-uniform curvature about which the piece of material is formed, a shoe for holding said piece of material in contact with said perimeter, resilient means for urging said shoe toward said contour forming block, said resilient means including a compressed air formin a guiding in a piece of material,

said piston andwithrespecttheretoassaidshoe follows the eccentric and non-planar erimeter of said rotating block. and means for balancing the weight of said shoe so that it may readily be moved from one plane to another by said rotating block.

6. In a machine for forming a compoimd bend a laminated rotatable contour forming block having a curved and nonplanar perimeter about which the piece of material is formed, a shoe for holding said piece of material in contact with said and restraining shoe through which said perimeter slides as it rotates yieldable means for urging said shoe toward said contour forming block, a resilient unlversal connection between said shoe and said yieldable means whereby said shoe may move both with said means and with respect thereto as said shoe follows the curved and non-planar pe of said rotating block. v

'1. In a machine for forming a compound bend in a piece of material, a rotatable contour forming block having a curved and nonplanar perimeter about which the piece of material is formed,

- a shoe for holding said piece of material in conted ' through which said shoe may tact with said perimeter, yieldable means for urging said shoe toward said contour forming block, and means of resilient material moimtins said shoe for horizontal, vertical and rotative movement, said shoe being mounted in a normally centered position, the resilience of said moimting material tending to return it to such position after any displacement therefrom.

, 8. In a contour forming machine in which a iece of material is forced to assume the contour of a form block carried by said machine, a pressure exerting shoe adapted to urge said material against said form block, and means mounting said shoe for horizontal, vertical and universal movement, said mounting means including track means upon which said shoe is guided in vertical and horizontal movements and resilient means twist in universal movement;

9. In a machine for contouring a piece of material, a rotatable contour forming block having which is curved and nonwhich said piece of mapressed air device for urging said shoe toward said contour forming block, said compressed device being so constructed that the shoe is reciprocated by said irregular perimeter as said forming block rotates, and a resilient universal connection between said shoe and said compressed air device.

CHARLES C. 

